The present invention relates generally to proton exchange membrane (PEM) fuel cells and particularly, to a method of addressing one membrane electrode assembly (MEA) failure mode by controlling MEA catalyst layer overlap, and the apparatus formed thereby.
Proton Exchange Membrane (PEM) fuel cell systems are currently being developed for use as power supplies in numerous applications, such as transportation, distributed and portable power, and co-generation. Such systems offer promise of economically delivering power with environmental and other benefits. Generally, successful commercialization of PEM fuel cell systems will need to exhibit not only adequate reliability in operation, but also durable system performance for many years of operation.
Component degradation reduces the reliability and performance of the fuel cell. One membrane electrode assembly (MEA) failure mode that can have an adverse effect of the durability of the overall fuel cell system is ionomer degradation (membrane material loss). Aside from the loss of power associated with one or more cells failing from voltage leaks, this situation poses reliability concerns. Accordingly, the present inventors have recognized a need for improvements in MEA design in order to provide a PEM fuel cell system with the improved durability.